Beach Nourishment Measurement and Payment

Category:

Surveying

This beach nourishment project involved placement of 1,920,000 yd3 of beach fill material

Description:

obtained from the Folly River behind the island, along 8,600 m of shoreline. The project had a

singular construction window in the winter between November 1, 1992 and May 15, 1993.

The template geometry for the beach renourishment was dynamic, rather than static, holding

constant the total number of cubic yards of fill for each linear foot of advance. This approach,

while rendering the final fill quantity more finite and predictable, substantially complicated the

placement of the fill material, and the computation of the pre- and post-dredge surveys.

A unique survey data collection system, the "surfboat," was used to acquire nearshore survey

data. The "surfboat" consisted of a 6-m broad-beam skiff equiped with dual-frequency (24/208)

echo sounder, and Del Norte Microwave positioning system. The unique feature of the surfboat

was the method by which heave was compensated for. A Spectra-physics plane laser was placed

above a point of known elevation, and a height instrument taken from the point to the infrared

light beam. As data were collected, a differential between the bottom of the receiver mast and the

point at which the receiver mast was intersected by the beam was recorded. The differential

measurement, combined with the known distance from the bottom of the mast to the face of the

transducer and the depth measurement, defined the vertical component of the measurement as an

elevation related to the project datum. This feature made additional reduction unnecessary.

Note: Survey boat, valued at $50,000, capsized and sunk during the operation. No one was

injured

Reviewer:

J. Lally

Company / Organization(s):

Access Restricted to U.S. Army Corps of Engineers

Projects Completed:

Folly Beach, Beach Nourishment Project

Location:

Folly Beach, South Carolina

Completion Date:

May 1993

Project Cost:

$8,200,000

Estimated Cost:

$5,000

Information Sources:

Literature:

Title:

"Beach Nourishment Project at Folly Beach, SC"

Author:

Billy L. Edge, Patric Johnson, and Charles W. Granger

Month:

Year:

1994

LitType:

Report/Proceedings

Publisher:

WEDA XV

Page:

255

Chapter 5 Other Technologies Reviewed